Developing sufficiency-based sharing principles for absolute environmental sustainability assessment using decent living standards and planetary boundaries

Absolute environmental sustainability assessments quantify the environmental impacts of human activities in relation to ecological carrying capacities. Such assessments necessitate the application of sharing principles to allocate shares of carrying capacity to actors and activities at different scales, including products, companies, sectors, and countries. This can help decision-makers set targets and take actions accordingly. Although a range of approaches exist, sharing principles that prioritize human needs fulfillment for all people are not properly developed. To address this gap, we develop sufficiency-based sharing principles. We do so by quantifying the life cycle impacts of satisfying decent living standards for the population of a high-income country in 2050 (Denmark) and comparing these impacts to planetary boundaries to identify a possible ‘sufficiency consumption space’. From this exercise, we infer two sharing principles. The first sharing principle assigns the allowed environmental impacts to all decent living standard consumption categories across 16 life cycle impact categories. The second sharing principle uses the degree of luxury of all goods and services in the economy, operationalized by expenditure elasticities, as a principle to share the sufficiency consumption space at a product-level. Together, these two sharing principles form a coherent suggestion for how to share a country's safe operating space, split between decent living consumption and remaining consumption. Our study thereby represents the first systematic and quantitative attempt at allocating a country's safe operating space according to human needs fulfillment and prioritizing a sufficiency consumption space according to the degree of luxury. Future research can address limitations of our study by, for example, using more granular life cycle inventory data and household expenditure data.